The present invention pertains to various types of image sensing devices that convert an object image into electronic data.
1. Description of the Prior Art
In general, compact video cameras and electronic still cameras are constructed such that the object image is converted into electric signals using an area sensor (a two-dimensional image sensing device). Further, line scanning-type cameras, in which a line sensor (a one-dimensional image sensing device) and a scanning mechanism such as a mirror rotation mechanism are combined, have conventionally been proposed for the purpose of high resolution image sensing (see Japanese Patent Publication Hei 4-67836). A camera of this type is capable of recording the entire image of an A4 size document in a manner such that the letters in the document may be legible.
2. Issues Addressed by the Invention
If high resolution image sensing is possible, the camera can be used for the recording of text information in various documents or writing on a blackboard, in addition to such general uses as image sensing of landscapes and people, which greatly increases the usefulness of the image sensing device. However, using a conventional device, the same operation settings are used in cases where the object is a landscape as well as cases where the object is a document. In other words, in setting the operating mode, no distinction has been made between general use in which image sensing of various objects is performed in a simple manner and image sensing intended to record the information of a document as well as its image (this will be called "image sensing of documents"). Consequently, the image quality of the recorded image and the recording format of the image data have been identical regardless whether it involved image sensing of a landscape or that of a document.
The present invention was made in consideration of the above problem. Its object is to provide a highly practical image sensing device that is capable of optimizing the quality of the recorded image depending on the nature of the object.